Income Taxes - Federal Statutory Tax Rate and Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense at statutory rate	$ 210	$ 231	$ 377
State income taxes, net of federal benefit	32	11	39
U.S. tax on undistributed non-U.S. earnings	6	6	20
Non-U.S. tax expense (benefit) on non-U.S. earnings	4	7	(28)
U.S. tax reform	0	(79)	874
Section 199 deduction	0	0	(18)
Loss on the sale of investment	0	0	(21)
Reserve for uncertain tax positions	(3)	2	3
Other provisions	(3)	8	7
Research credits	(10)	(9)	(4)
Stock compensation	(27)	(30)	(14)
Valuation allowances	(79)	(14)	(8)
Total income tax expense	$ 130	$ 133	$ 1,227
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax expense at statutory rate	21.00%	21.00%	35.00%
State income taxes, net of federal benefit	3.20%	1.00%	3.60%
U.S. tax on undistributed non-U.S. earnings	0.60%	0.50%	1.90%
Non-U.S. tax expense (benefit) on non-U.S. earnings	0.40%	0.60%	(2.60%)
U.S. tax reform	0.00%	(7.20%)	81.20%
Section 199 deduction	0.00%	0.00%	(1.70%)
Loss on the sale of investment	0.00%	0.00%	(2.00%)
Reserve for uncertain tax positions	(0.30%)	0.20%	0.30%
Other provisions	(0.30%)	0.70%	0.70%
Research credits	(1.00%)	(0.80%)	(0.40%)
Stock compensation	(2.70%)	(2.70%)	(1.30%)
Valuation allowances	(7.90%)	(1.30%)	(0.70%)
Total income tax expense (benefit), percent	13.00%	12.00%	114.00%